The present invention relates in general to equipment and methods for testing filters, and in particular to a new and useful apparatus and method for testing a gas mask filter under simulated breathing conditions and using test animals.
The effectiveness of a gas mask filter can be tested using a constant flow apparatus but this does not simulate the variations in pressure to which the filter would actually be exposed under the effects of human respiration. In attempting to reproduce realistic conditions test animals may be used in determining the effectiveness of such filters. Scaled down models of the filters may be used. Some filters however cannot be scaled down effectively. The model M13A2 gas mask filter for example cannot be scaled down using appropriate charcoal.
A way to avoid the use of test animals is to chemically analyze the filter effluent. This however may not detect toxic materials or it may indicate the presence of a compound of unknown toxicity. Consequently, chemical analysis alone may give an incorrect estimate of the protective capacity of the filter.
Even where test animals are utilized, however, toxic signs in testing for the effectiveness of the filter may not demonstrate sensory irritation suffered by the animal.
The apparatus and method of the present invention solves the foregoing problems.